用户指南和参考

ST_CoordDim

ST_CoordDim 返回 ST_Geometry 值的坐标维数。有关坐标维数的解释,参见

语法

db2gse.ST_CoordDim(g1 db2gse.ST_Geometry)

返回类型

整数

示例

创建具有 geotype 和 g1 列的 coorddim_test 表。 geotype 列存储 g1 几何图形列中存储的几何图形子类的名称。

CREATE TABLE coorddim_test (geotype varchar(20), g1 db2gse.ST_Geometry)

下列 INSERT 语句将样本子类插入 coorddim_test 表。

INSERT INTO coorddim_test VALUES(
    'Point', db2gse.ST_PointFromText('point (10.02 20.01)', db2gse.coordref()..srid(0))
)
 
INSERT INTO coorddim_test VALUES(
'Linestring',
       db2gse.ST_LineFromText('linestring  (10.02 20.01,10.32 23.98,11.92 25.64)',
                         db2gse.coordref()..srid(0))
)
 
INSERT INTO coorddim_test VALUES(
'Polygon', db2gse.ST_PolyFromText('polygon ((10.02 20.01,11.92 35.64,25.02 34.15,
19.15 33.94,10.02 20.01))', db2gse.coordref()..srid(0))
)
 
INSERT INTO coorddim_test VALUES(
'Multipoint', db2gse.ST_MPointFromText('multipoint (10.02 20.01,10.32 23.98,
11.92 25.64)', db2gse.coordref()..srid(0))
)
 
INSERT INTO coorddim_test VALUES(
'Multilinestring', db2gse.ST_MLineFromText('multilinestring ((10.02 20.01,
10.32 23.98,11.92 25.64),(9.55 23.75,15.36 30.11))', db2gse.coordref()..srid(0))
)
 
INSERT INTO coorddim_test VALUES(
'Multipolygon',
       MPolyFromText('multipolygon (((10.02 20.01,11.92 35.64,25.02 34.15,
19.15 33.94,10.02 20.01)),((51.71 21.73,73.36 27.04,71.52 32.87,
52.43 31.90,51.71 21.73)))', db2gse.coordref()..srid(0))
)

该 SELECT 语句列示 geotype 列中存储的子类名和该 geotype 的坐标维数。

SELECT geotype, db2gse.ST_coordDim(g1)' coordinate_dimension'
FROM coorddim_test
 
GEOTYPE        coordinate_dimension
-------------------- --------------------------
ST_Point                                 2
ST_Linestring                            2
ST_Polygon                  2
ST_Multipoint                            2
ST_Multilinestring                       2
ST_Multipolygon             2
 
6 record(s) selected.


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